Delay powder



Patented May 12, 1931- UNITED- STATES" 'enoaen c. HALE, or Down, mm mmDELAY rowmm Ho Drawing.

Application filed January 8, 1925. Serial No. 462.

(GRANTED UNDER THE ACT OF MARCH 3, 1883, AS AMENDED APRIL 30, 1928; 8700. G. 757) The invention described herein may be manufactured and usedby or for the Government for governmental purposes without the paymentto me of any royalty thereon.

The subject of this invention is a delay powder intended for useprimarily in fuses.-

The powders heretofore used for delay powder trains, one of theprincipal uses of such powders being in time train fuses, gave uniformlygood results until the advent of aircraft into warfare and theconsequent necessity of propelling projectiles into the upper strata ofthe atmosphere where the air is more rarefied and the atmosphericpressure consequently reduced.

Under these circumstances it is found that the fuses give very erraticfunctioning re-.

tus which is partially evacuated. In a'16" vacuum the burning time ofthe fuse at full setting is approximately ll seconds slower than underatmospheric pressure. Under these conditions some of the fuses fail toburn through completely. Thus it seems that it has practically beenproven that low pressure is responsible for the erratic action of thefuses in firing tests.

Efforts have been made to overcome this difficulty by altering thecomposition of black powder in such a way as to obtain powders whichwill give a higher temperature upon 40 burning and greater ease ofignition. While a some improvement was effected in this manner no powderwas obtained which would burn uniformly under reduced'pressure.

By departing entirely from the typeof powders just referred to, it hasbeen mind that the difliculty can be overcome. To obtain this result itis proposed to provide a powder composed of substances one or more ofwhich will decompose, when decomposition is once started, and others ofwhich will combine with the gases evolved on decomposition, the chemicalreactions taking place evolving suflicient heat to insure a continuationof the reactions until the train is completely converted. The result ofthese chemical reactions is the production of solids rather than gases.

Powders combined in this way are found to burn uniformly even inrarefied air and accuracy of the setting of a time fuse having such apowder train is greatly enhanced.

A powder of this character loaded into the regular time fuse has burnedthrough both rings completely in about 17.5 seconds, the extremevariation among all the fuses fired being only 0.4 seconds under a 16"vacuum. t has, consequently, been shown that such powders have unusualpossibilities for use in time fuses.

The following are given by way of example of powders constructed orcombined in accordance with this invention. P t

" er Cell 1. Red lead 84A Silicon 14.8 Glycerine 0.8 The burning of thispowder may be represented by the following-formula:

as a result of decomposition. Per cent 5 2. Barium peroxide 83 Magnesium12 Shellac 5 3. Red lead 88 Calcium silicide 10 Resin" 2 4. Red lead 79Ferro-silicon 12 Aluminum 9 5. Lead peroxide i. 86

Calcium silicide 1410c It will be readily realized by those familiarwith this art that other gas producing compounds than those mentionedabove may be substituted therefor and that other substances may besubstituted for the silicon, aluminum and magnesium, and it is withinthe spirit of this invention to make such substitution when desired.

I claim:

1. A delay powder for time fuses embodying an oxide of lead, silicon anda substance capable of reacting with the lead oxide and forming abinder. v

2. A delay powder for time fuses including an oxide of lead, siliconandglycerine.

3. A delay powder for time fuses embodying a metallic oxide and asilicon com ound capgble of combining with oxygen to f drm a soli a 4. Adelay powder for time fuses embodying an oxide evolving oxygen upondecomposition of such oxide, a silicon compound capable of reacting withoxygen to form a solid and a binder.

5. A delay powder for time fuses embodying an oxide, silicon capable ofreacting with oxygen to form a solid and a substance uniting with anelement of the oxide to form a chemical compound and forming a binder.

6. A delay powder for fuses embodying a metallic oxide, a mineraladapted to react with oxygen to form a solid and 'Iycerine.

GEORGE c? n.

